Problem Cause

Untrusted Font Blocking is a new feature of Windows 10 that can be deployed throughout organizations using a group policy. A TechNet article describes a scenario that can occur when visiting certain websites:

Using Internet Explorer to look at websites that use embedded fonts. In this situation, the feature blocks the embedded font, causing the website to use a default font. However, not all fonts have all of the characters, so the website might render differently.

Testing

A simple way to test whether the Untrusted Font Blocking setting is causing your icon display issues is as follows:

Try visiting your WebFront instance using a different operating system, such as Windows 7 or MacOSAlthough this group policy can be set on all Windows machines, its effects are seen only in Windows 10 or later releases. If the icons appear in Windows 7, for example, you probably have this setting enabled.

Solution

Because WebFront is not currently compatible with the Enabled setting of the Untrusted Font Blocking feature, ensure that this feature is set either to Disabled or to Not Configured.